Various springs and spring assemblies have been developed for providing a resistance or assistance force for devices such as chair tilt mechanisms, height adjustment mechanisms for chairs and tables, door opening/closing mechanisms and other applications requiring an assistance or resistance force. Due to production tolerances and other such variables, the amount of force generated by a spring may vary from one spring to another. This can lead to inconsistent resistance forces assemblies such as office chairs, height adjustable tables, or other devices or products that utilize springs.